Underreamer.



No. 892,905. MTBNTED JULY 7, 1908. 3.3. SIMPSON. UNDBRRBAMER. APPLICATION FILED JAN.19, 1906.

` 2 SHEETS-SHEET 1.

No. 892,905. PATENTBD JULY 7, 1908.

R. E. SIMPSON. 1

UNDERREAMER'. l

lI. LI A 0N F D .l A P O TI ILE JAN 9 1906 ZSHBETSaSEEET 2' wzee: Inma/@Z071 www . same in expanded position, and for breakable parts SIMPSON, a citizen sldmg at Bakersfield, in the county of Kern UNITED STATES PATENT OFFICE.

UNDERREAMERL Specification of Letters Patent.

Patented July 7, 1908.

Application led January 19, 1906. Serial N o. 296,759. I

concern: a i

at I, ROBERT EDWARD of the United States, re-

To all whom Vit ma Be .it .known tii andState of California, have invented a new and useful Underreamer, of which the followingis a specification. his lnvention relates to that class of underreamers adapted for reaming the hole below a well-casingn to allow the casing to descend. Means'are provided for positively expandlng the cutters, for positively holding the ositively retractingthecuttersfromexpande position.

. y Itis of the objects of this invention to prohave no liable to come in contact withstones or other solid substances with Whichthe cutters come in contact while doing their work.

, provide a safety pin which acts as a positlve expander and a positive reducer for expanding and reducing the size of the underreamer, the same belng located in position where it cannot come in contact with boulders, gravel, stones, or other objects which might break or bend the same, and .being arranged to prevent the cutters, the cutter-carrying plunger and other parts from falling out in case of accident to the plunger, its support, or its s ring; also to secure maximum strength wit v minimum size of mandrel and other parts also to provide for maximum collapsing of the too and certain positive olpenlng or explanding. when ettin below t e bottom of t e open end of lt e we -casing or pipe; also to rovide an improved. construction in whic side on a perfect hinge and are adapted to vide yan 'underreamer which will collapse completely inside the diameter of the'mandrel or bo The invention comprises the underreamer, i

the combinations, and the parts hereinafter more particularly described.

I do not limit myself to the exact construction shown and described, but may vary the construction without departing .from .y the spirit of the invention. n

The accompanying drawings illustrate the invention.

Figure 1 is a View of the underreamer, looking at the outer face of one of the cutters, the same bein in expanded osition'. Fi .-2 is a fragmenta view at rig tangles to ig. 1,

.showing the underreamer in a well casing.

.position of having a forked man the cutters work side by Fig. l3 is a fragmental, longitudinal, axial section on line 3-c3, Figs. 1 and 4, showing the parts when the cutters are expanded. F1 4 is a view looking lup from the bottom o Fig. 3, showin the tool intact. Fig. 5 is a cross section on ine indicated by :c5-fc5, Fig. 3, the cutters being expanded. Fig. 6 is' a fragmental detail partly in axial mid-section on line indicated by -x, Figs. 3 and 4. Fig. 7 is an end view of the body of the underreamer. Fig. 8 is a view looking down on one ofthe cutters detached. Fig. 9

is an elevation of one side of one of the cutters. Fig. 10 is a sideelevation of the other side of a cutter. Fig. .11 is an elevation of the inner face of either cutter. fragmental, axial section of the lower end of the underreamer body. Fig. 13 is a cross section on line mls-, Fig. 3. Figs. 8, 9, 10, and 11, are on a larger scale than the other views.

Theinvention com rises `an underreamer diel or body 1 and ex. panding cutters 100 movable in the mandrel and having bits 2 and Shanks 5, and constructed to form a tie or brace for the forks,

yprongs or jaws 3 of the mandrel body when the cutters are expanded. Preferably, the cutters are constructed to interlock with the jaws Iwhen the cutters are expanded, thereby tying the cutters and jaws'tightly together and preventing any looseness, rattling or Fig. 12 is a strain on any partv not integral with the mandrel body or with the cutters.

The expanding cutters 100 are duplicates and constructed to be slidingly mounted between the jaws 3, and to Vembrace the ends of the jaws when the cutters are expanded. To this end the lower ends or tips 4 of the jaws are rounded to spread the, cutters a art, and the cutters are provided with shan s 5 constructed to fit between said jaws and are provided\w.ith portions to en seat the rounded ends of t e jaws to expand `the cutters and to tie and brace the jaws; said cutters are provided with slots, grooves, and recesses or pockets to receive, retain, and to be held by other parts of the underreamer, as will be hereinafter more fully set forth.

The shank 5 of each 'cutter is located wholly on one side 'of the longitudinal midline or` axis of the cutter, and the combined thickness of the two Shanks is practically e ual in width to the s ace between the jaws o? the forked body. ach cutter is provided panded positon,

on one side of its shank with a recess 6 and on the other side o f the shank with two recesses 7, 8, and a rib 9 between them. The outer walls 10, 11, of the recesses 6, 7, are adapted to seat and engage the rounded ti s 4 ofthe jaws to center the cutters and old them solidly in place on the end of the body when the cutters are expanded.

The jaws are duplicates and each is provided with a flat slanting rib 12, a channel 13 at one side thereof, and a straight rib 14 at the upper end of the channel 13. The shank of eac cutter is provided with a rib 15 to enter a seat or pocket 16 forming the up er portion of channel 13 of either jaw, and? is also provided with a seat 17 for the mandrel rib 14.

The shank 5 of each cutter 10() is provided with a circular seat 18 and a tapering way 19 for the spring-actuated plunger 2O which is vprovided with a circular cross-head 21, and upon which the cutters arehin ed or pivoted and byv which they are norma ly held in exas shown in Fig. 3. The upper portion of the circular seat 18 in each shank 5 forms an inwardly-projecting shoulder under which cross-head 21 takes, and

thus provides means for pivotally supporting4 the cutters. Each cutter shank is also provided with a bent slot 22, the lower portion 23 .of which extends at right angles to the face 24 of the upper end of the cutter shank, and the upper end 25 of which slot-extends toward the edge of the shank on which the cutter is mounted. By reason of the lower vportion of the slots 22 extending longitudi- .nally of the shanks of the cutters each cutter shank 5 is guided along pocket 16 and is not changed with respect to its angular position until ytherib 15 leaves the pocket 16. s 26 is a pin having a head 27, and inserted through one and screwed into the other of the jaws 3. A socket 28 is provided in one of the 'aws to seat the head 27 of the in when t e said pin is screwed into the ot ier jaw. Said pin extends through the bent slots 22 of the cutters, and when the cutters are drawn up by the usual spring 29 acting through the plunger 20, the pin 26 will engage the lower ends of the upper ends of the Shanks engage and solidly seat against the lower end of the mandrel.

The wall 30 of the plunger way 19 which is nearest the edge of the shank to which the cutter is attached may be at right angles to the upper face 24 of the shank, while the opposite wall 31 is' oblique to said upper face, so that when the cutters are drawn down to bring the in 26 into the oblique portions 25 of the s ots 22 the cutters may swin on the circular head 21 of the plunger to a low the cutters to move toward each other.

By the construction shown, whenever the cutters are drawn down, as shown in Fig. 2,

ation.

the bent slots, while they will beforced to close toward each other and will be held closed until the cutters are released, whereupon the spring 29 will force the cutters upward and the pin 26, entering the lower portion 23 of the slot 22 will bring the cutters into position to cause the interlocking of the same with the prongs of the mandrel 1.

` Each of the cutters is provided with a shoulder 32 to engage the bottom of thewellcasing 41 when the underreamer is drawn up to withdraw the same from working position.

34 is a block fastened in the end of the plunger-chamber 35 by dowel pins 36.

To assemble the tool, thecutters will be placed with the inside flat faces 37 together and on opposite sides of the plunger and its head to chamber the head 21 and lower the neck of the'plunger in the circularsockets 18 and the flaring or ta ering ways 19 at the upper end of the shan s; the spring`29 and block 34 and nut 38 being in place, said nut being secured by a cotter-pin 39. Then the bits 2 of the cutters will be spread apart and the safetypin 26 will be .brought tothe lower end of the slot 22, and the flat faces 24 of the upper ends of the Shanks will be brought against the flat face 40 of the lower end of the mandrel body 1 at the upper ends of the jaws. Then the dowel pins 36 will be inserted, and the tool is ready for oper- To insert it in a well-casing 41, the cutters will be forceably retracted to the position shown in Fig. 2, and thereu on the tool may be inserted into the we l-casing and lowered until the reamer comes below the shoe 42 of the casing, whereupon the cutters will expand to the position indicated in Fig. 3, and the tool is ready for operation. I

When it is desired to withdraw the underreamer from the casing, the upward movement of the same will bring the shoulders 32 against the lower edge of the shoe 42 thus, as the mandrel is withdrawn ,the pin 26 .acts on the cutters through the slots 22 to positivel retract the cutters from their expan ed osition until theshoulders 32 are retracte within the mandrel, whereupon or sooner they escape the sh'oe and pass on up through the casing.

What I claim is :-`v

1. A forked underreamer mandrel terminating in two jaws, and cutters provided with Shanks between said jaws and with portions adapted to embrace and tie together' the ends of said jaws when the cutters are expanded. y

2. A forked under-reamer mandrel terminating in two jaws the ends of which are rounded, cutters provided with shanks between'l said jaws and with portions to embrace the rounded ends of the jaws toexpand the cutters and tie the jaws together.

' 3l. An `u nderreamer comprising springactuated cutters having reversely-bent slots, -a p ortion ofeach extending longitudinally of end,cutters slldably mounted between the jaws and lprovided with reverSely-bent slots, a pinin t e jaws and bent slots, and means for forcing the cutters to engage the rounded ends of the jaws for expanding the cutters.

' 5. An underreamer comprising a forked mandrel, provided with jaws, eac having a flat slanting rib 12, a channel 13 at one side f thereof and a straight rib 14 at the upper end of the channel, and cutters mounted between-the jaws of the mandrel and provided with ribs 15 to enter the upper portions of channels 13, and also provided with seats 17 for the mandrel ribs 14.

6. An underreamer cutter having ashank land a bit that projects laterally from one A edge of the shank, and a rib that projects laterally and inwardly from the shank toform a recess to receive a portion of'a mandrel.

' 7. An underreamer comprising a charnbered 'forked mandrel, a sprin su ported provide wit a cir` ed between Said jaws and provided with circular sockets for the cross-head and with a .channel for the stem of the plunger.

8. An underreamer comprising a forked mandrel, cutters provided with bent slots and arranged between the jaws of the mana drel, la pin 1n the jaws and slot, and means for moving the cutters lengthwise ofthe jaws.

9.' A n underreamerl comprising a forked mandrel, cutters movable in the mandrel and each provided with a shank located wholly on one side of Ithe longitudinal midline or axis of the cutter, the combined thickness of the two Shanks being practically equal in width to the space between the jaws of the mandrel, each cutter being provided on one Side of the shank with a recess 6 and on the other side of the shank with the two recesses 7, 8, and a rib 9 between them, the outer walls of the recesses being adapted to seat and engage the tips of the jaws.

10. An underreamer comprising a forked chambered mandrel, they inner faces of the jaws of said mandrel being provided with a channel and a ocket, cutters each provided with a slotted s iank one face of which is provided with a .rib fitted to the channel and pocket and the other face of which shank is provided with a socket and way for the cross-head and plunger of the cutter-su porting means, the inner sides of said shanlS eing adapted to move upon each other, a plunger having a cross-head in said socket, and means for guiding the Shanks to expand and contract the cutters as they are'rnoved lengthwise between thejaws. l

11.An underreamer. provided. with movable cutters having Shanks provided with bent slots, having lower portlons 'extending longitudinally of the cutter Shanks and a pin through said slots to expand and contract the cutters as the same move lengthwise of, A

the underreamer.

12. A forked underreamer mandrel havy ing the endsof its forked jaws rounded, and

cutters having recessesto seat 4and engage the rounded ends of the jaws.

In testimony whereof, I have hereunto set4 my hand at Bakersfield California this '12th' day of Jane 1.906.

In .presence of- JOHN GUNDRoD, FRANK. GRAY. 

